This invention relates to an improved thread guide means in a take-up lever for sewing machines which guide means is so constructed as to prevent displacement or threading-out of the sewing thread from the guide means during a sewing operation.
Conventional sewing machines embodying rotating oscillating shuttle hooks generally are provided with take-up levers having a closed thread eyelet or aperture through which the thread extending between the supply spool and the needle is guided. The provision in a take-up lever of a slotted arrangement, instead of a closed eyelet, which would make it possible to guide the thread between the supply spool and the needle eye, in a single step, without requiring inserting the thread into a closed eyelet, would be a decided advantage to an operator in the operation of the machine. However, in rapid sewing, the thread guide in the end of the take-up lever, in its path of travel, attains a high velocity and the use of a closed eyelet is required to insure against threading-out of the thread from the guide.
Attempts have been made to provide take-up levers with threading slots communicating with a thread guiding eyelet. Such construction is exemplified in U.S. Pat. No. 3,310,015 issued Mar. 21, 1967. However, it has been found that such constructions are not completely effective to prevent threading-out during high speed operation of the machine.
In accordance with the present invention I provide a thread guide in a take-up lever which affords the advantages of a slot construction for convenient and easy threading and which through the provision of one or more detents retains the thread against inadvertent displacement even during high speed operation of the machine.
It is an object of the present invention to provide an improved thread guide in a take-up lever for a sewing machine, the guide having a slot for conveniently accepting the thread and one or more detents for retaining the same during high speed operation of the machine.
Another object of this invention is the provision of a take-up lever which is simple and rugged in construction and economical to manufacture.
Other and further objects of this invention will become apparent from the following description when considered in connection with the accompanying drawings.